Feed module including an envelope closure device that retains water

ABSTRACT

A feed module for feeding envelopes into a mail handling machine, which feed module comprises envelope conveyor means for conveying said envelopes through the feed module, separator means for selecting said envelopes one-by-one, moistener means for moistening a flap of the envelope selected in this way, and closure means for pressing the envelope closed and for ejecting it from the feed module, said closure means comprising two superposed extractor rollers, each of which has a respective ribbed portion that is made of a hydrophobic material and that extends over a width corresponding to at least the width of a print zone in which the postal imprint is to be printed.

TECHNICAL FIELD

The present invention relates to the field of mail handling, and it relates more particularly to an envelope feed module provided with an improved device for conveying envelopes and for closing envelope flaps.

PRIOR ART

Conventionally, and as shown diagrammatically in FIG. 2, in a conventional mail handling machine, envelope flaps are closed by pressure from the extractor rollers disposed at the outlet of the envelope feed module of said machine, after the inside faces of the flaps have been moistened by a moistener device disposed immediately upstream from said rollers on the path along which said envelopes are conveyed.

Unfortunately, the simplicity of that envelope flap closure system gives rise to a major drawback. The inventors have observed that, with that system, the surplus water expelled by the extractor rollers during closing finds itself on the conveyor zones, and the immediately following envelope picks up the stagnant water and, on falling into the collection tray, that following envelope degrades the printing of the postal imprint on the envelope preceding it by a phenomenon known as “offsetting” or “smudging”.

The consequences of such smudging of the printing of the postal imprint are serious insofar as the envelope whose postal imprint is smudged can no longer be decoded by optical reader means and might therefore be rejected by the postal authorities even though payment therefore has been deducted.

Object and Definition of the Invention

An object of the present invention is thus to mitigate those drawbacks in envelope closure by proposing a mail item feed module provided with a device for closing envelope flaps that is both simple and reliable, and that avoids smudging. Another object of the invention is to propose a device that makes it possible to close envelopes without using additional external means. Another object of the invention is to propose a device that does not involve a decrease in the initial compactness of the feed module.

These objects are achieved by a feed module for feeding envelopes into a mail handling machine, which feed module comprises envelope conveyor means for conveying said envelopes through the feed module, separator means for selecting said envelopes one-by-one, moistener means for moistening a flap of the envelope selected in this way, and closure means for pressing the envelope closed and for ejecting it from the feed module, wherein said closure means comprise two superposed extractor rollers, each of which has a respective ribbed portion that is made of a hydrophobic material and that extends over a width corresponding to at least the width of a print zone in which the postal imprint is to be printed.

The presence of the ribbed rollers makes it possible to close the envelopes without smudging the printing on them, and, by not bringing any water into the print zone, thus ensures that the postal imprint printed downstream remains intact, thereby guaranteeing that it can be recognized properly by optical reader means.

Advantageously, said ribs on said top extractor roller and said ribs on said bottom extractor roller are offset such that no contact can exist between them while said envelope is being closed.

Each of said extractor rollers may have a ribbed portion over a length greater than the width of said flap.

Said hydrophobic material is chosen from among the following materials: polyoxymethylene, expanded polystyrene, Teflon®, and Versilic® silicone.

Each of said extractor rollers further has a smooth remaining portion made of a material having a high coefficient of friction in order to convey the envelopes properly.

Preferably, said ribbed portion and said smooth portion are mounted to rotate about a common axis of rotation, and, disposed at least under said ribbed portion of said bottom extractor roller, a squeegee is provided for removing surplus water to a drainage channel in order to recycle said surplus water.

Advantageously, said drainage channel is also extended under said smooth portion of said bottom extractor roller.

Said extractor rollers are preferably connected mechanically to said envelope conveyor means via a movement transmission mechanism.

The invention also provides a mail handling machine including such an envelope feed module. The machine may be a franking machine or “postage meter”, or indeed it may be a folding and stuffing machine.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the present invention appear more clearly from the following description given by way of non-limiting indication and with reference to the accompanying drawings, in which:

FIGS. 1A and 1B are respectively a plan view and a section view showing a preferred embodiment of the rollers for closing envelopes in accordance with the invention; and

FIG. 2 is a diagrammatic longitudinal section view showing a prior art feed module.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

FIG. 2 is a highly diagrammatic view of a prior art feed module 10 for feeding envelopes 12 into a mail handling machine. That feed module comprises a series 100 of drive rollers that direct the envelope 12 (as slightly inclined and jogged from behind on a feed plate 14 provided with a stack of such envelopes) towards and under separator means 102 conventionally comprising a guide 104 and superposed selector rollers 106, 108 for selecting the envelopes one-by-one. Conveyor means comprising in particular a presser assembly 110 and superposed drive rollers 112, 114 convey each selected envelope towards moistener means 16 for moistening the envelope flaps. In the example shown, and as is known, such a moistener device comprises a separator 140 having a stationary portion 142 secured to the body of the feed, and a hinged portion 144 provided with a brush 146 whose bristles, directly in contact with a moistener reservoir 148 in the absence of envelopes then comes to moisten the inside portion of the flap of each of the envelopes after said flap has been moved away from the body of the envelope by the separator 140. A vertical wall 150 parallel to the direction in which the envelopes are conveyed forms a referencing wall for laterally guiding (jogging) the envelopes. Immediately downstream from the moistener means, two superposed extractor rollers 116, 118 are mounted that are connected mechanically to the conveyor rollers 112, 114 of the pressure assembly 110 by a movement transmission mechanism 120.

This mechanism 120 makes it possible to transmit the spacing between the conveyor rollers, which spacing depends on the thickness of the envelope, to the extractor rollers 116, 118 with a determined gear ratio that is chosen to procure simultaneously both taking account of varying envelope thicknesses and also maintaining sufficient pressing stress to press the flap of the envelope against the body thereof progressively.

Naturally, connection means 18 are also provided at the outlet of the feed module 10 so as to form, in the mail handling machine, a mechanical link and continuity in the electrical links with the immediately following module, e.g. a franking module 20, of which only the two superposed take-up rollers 200, 202 are shown.

In accordance with the invention, the extractor rollers are not uniformly smooth, but rather each of them has a ribbed portion 34, 36 mounted to rotate about a common axis of rotation 30, 32 shared with the remaining portion of the corresponding extractor roller, the width of each ribbed portion corresponding to at least the width of the print zone of the postal imprint (and typically to slightly greater than the width of a flap of the standard trapezoid-shaped type), which ribbed portion is made of a hydrophobic material such as polyoxymethylene, expanded polystyrene, Teflon®, or indeed Versilic® silicone, the remaining portions 38, 40 of the rollers being smooth, as above, and being made of a material having a high coefficient of friction, such as natural rubber, silicone, or polyurethane, in order to convey the envelopes properly.

The ribs on the top extractor roller and the ribs on the bottom extractor roller are mutually offset so that no contact is possible between them in those portions of the rollers that are closest to the referencing wall 150. Thus, it is impossible for water to be deposited on the ribbed portion of the top extractor roller, and thus it is impossible for water to be deposited on the top portion of the envelope on which the postal imprint is to be printed.

In addition, at least under the ribbed portion 36 of the bottom extractor roller 118, provision is made to mount a squeegee 42 advantageously made of silicone or of polyurethane for scraping off any surplus water present on the bottom extractor rollers, and for removing such water to a drainage channel 46 in order to recycle it, e.g. to the moistener reservoir 148. The drainage channel can also advantageously be extended under the smooth portion 40 of the bottom extractor rollers and then be provided with another squeegee 44.

The feed module of the invention operates as follows. The loaded envelopes inserted in stacks into the feed module from the loading tray are, after being selected one-by-one, directed towards the separator of the moistener device where the flap of the selected envelope is firstly moved away from the body of the envelope before said flap is moistened by the brush. The envelope is then extracted by the extractor rollers between which said envelope is simultaneously closed before being ejected from the feed module, e.g. towards the franking module disposed downstream.

The flap being closed by pressure from the extractor rollers, i.e. by pressure being exerted on the flap of the envelope by the ribs of the ribbed portions of said extractor rollers, causes the surplus water to be driven away to the outside of the flap and thus essentially towards said ribbed portions of the rollers. The surfaces of said ribbed portions would tend to be coated with a fine film of water, but due to the hydrophobic nature of the material of which said ribbed portions are made, said water does not remain pressed against the ribs but rather it runs off towards the drainage channel, from which said surplus water is then recovered, preferably for recycling.

Naturally, the invention is not limited to the above-described preferred embodiment. In particular, it is possible to make provisions to replace the brush moistener means with water-jet moistener means without going beyond the ambit of the invention. 

1. A feed module for feeding envelopes into a mail handling machine, which feed module comprises envelope conveyor means for conveying said envelopes through the feed module, separator means for selecting said envelopes one-by-one, moistener means for moistening a flap of the envelope selected in this way, and closure means for pressing the envelope closed and for ejecting it from the feed module, wherein said closure means comprise two superposed extractor rollers, each of which has a respective ribbed portion that is made of a hydrophobic material and that extends over a width corresponding to at least the width of a print zone in which the postal imprint is to be printed.
 2. A feed module according to claim 1, wherein said ribs on said top extractor roller and said ribs on said bottom extractor roller are offset such that no contact can exist between them while said envelope is being closed.
 3. A feed module according to claim 1, wherein each of said extractor rollers has a ribbed portion over a length greater than the width of said flap.
 4. A feed module according to claim 1, wherein said hydrophobic material is chosen from among the following materials: polyoxymethylene, expanded polystyrene, Teflon®, and Versilic® silicone.
 5. A feed module according to claim 1, wherein each of said extractor rollers further has a smooth remaining portion made of a material having a high coefficient of friction in order to convey the envelopes properly.
 6. A feed module according to claim 5, wherein said ribbed portion and said smooth portion are mounted to rotate about a common axis of rotation.
 7. A feed module according to claim 5, wherein, disposed at least under said ribbed portion of said bottom extractor roller, it further comprises a squeegee for removing surplus water to a drainage channel in order to recycle said surplus water.
 8. A feed module according to claim 7, wherein said drainage channel is also extended under said smooth portion of said bottom extractor roller.
 9. A feed module according to claim 1, wherein said extractor rollers are connected mechanically to said envelope conveyor means via a movement transmission mechanism.
 10. A mail handling machine including an envelope feed module according to claim
 1. 